Packaged vehicle lift



Sept. 26, 1961 J. D. COCHIN PACKAGED VEHICLE LIFT Filed April 1, 1960 Fig. I.

2 Sheets-Sheet 1 Sept. 26, 1961 J D COCHIN 3,001,512

PACKAGED VEHICLE LIFT 2 sheet 2 Filed Apri 1 960 INVENTOR Un a es 3,001,512 PACKAGED VEHICLE LIFT John D. Cochin, 205 E. Grand Ave., South San Francisco, Calif.

Filed Apr. 1, 1961 Ser. No. 19,273 12 Claims- (Cl. 121--46) This invention relates to a substantially pre-assembled ready-to-install vehicle lift. i The present invention relates generally to a vehicle lift of the type having a vertically reciprocally movable piston mounted within a cylinder in which the cylinder is mounted below ground or floor level so that a vehicle supporting super-structure orbolster carried by-the piston may be raised or lowered with the piston from the ground surface. Such lifts are conventionally used for example in service stations and garages for lifting automobiles, trucks and other vehicles for the purpose of lubrication and repair to the underparts of the vehicle. u In more conventional type lifts, the lift is operated by compressed air supplied to the cylinder from a com,- pressor source located some distance away from the lift itself. To install such a lift it is necessary to custom plan and install air pipes and valves leading from the compressor source to the cylinder which must be suitably located underground or out of the way so as not to inter: fere with operation of the lift or with access areas and. working areas adjacent thereto. Such typesof conventional lifts require special skill andexperience on the part of the persons who undertake to design and install the air pipe plumbing system according to the local cir-* cumstances and requirements peculiar to each particular installation.

A broad object of the present invention is to provide what may conveniently be termed a packaged lift structure in which substantially all of the parts, particularly including the pneumatic-hydraulic lines and related control valve system, are factory assembled and ready forv installation at the ultimate site without requiring any custom design or installation of the type so often required in prior art practices.

Stated more specifically, a primary object of the invehtion is to provide an integral lift unit which incorporates a built-in or factory assembled pneumaticcontrol system including air lines leading from a ground level point of connection to a control valve located at'any desired location away from the lift, to the piston-cylinder.

of the lift itself, the arrangement of lines and} valves being such as not to interfere with the operation of the lift itself or with any accessor work area withinthe vicinity of the lift. In this connection there is provided a novel tubular guide which is attached to the elevated superstructure of the lift itself and which is reciprocally vertically movable within a sunken easing or Welland which carries and houses the pneumatic lines from approximate-- ly."-ground or floor level to the piston, and which said tubular guide also functions to prevent the super-structure or bolster fromrotating about the axis of the piston. Another object is to provide a check valve in the hydraulic system which will function to lock the piston in an elevated position even should the pneumatic pressure within the piston drop to atmospheric level. A feature of the invention is the provision of a release mechanism which functions to release both the check valve and the air pressure within the piston in order to lower the lift. i V Another specific feature and advantage is that the prionmatic lines to the lift are connected to a flexible hosing located within a tube depending from the super-structure of the hoist and extending upwardly to the super-strum.

ture on the piston so that there is provided a flexible pneumatic linkage located Within the tube with the fur- Patented Sept 26, .1961

"ice

ther provision of the tube being reciprocally movable within a casing. pipe located below the ground surface in such a way as to prevent rotation of the super-structure.-

One of the principal advantages of this invention is that the hoist is held in each of its relative elevated positions by both an air and a hydraulic lock, each said lock being effective to maintain the hoist in the elevated position independently of the other.

Another feature of this invention is that the flexible air hose makes air contact between the top portion of the piston and the floor by the use of slack take up means which hold the length of hose between the floor level and the hoist under tension so that the hose maintains an adjacent parallel relationship to the piston throughout all phases of piston movement.

Other objects of the present invention will become: apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views. p

In the drawings: f

FIG. 1 is a sectional view of the lift of this invention, FIG. 2 is a cross-sectional view of a fragmentary por; tion of FIG. 1 taken at line 2-2.

FIG. 3 is a similar cross-sectional view taken at line 3-3. I

FIG. 4 is a sectional view of the actuating pneumatic; and hydraulic actuating valves for controlling the liftl.

FIG. 5 is a top plansectional view of the actuatingvalve of FIG. 4. 1

'FIG. 6 is a cross-sectional view of the valves of FIGS. 4 and 5 taken at line 6-6.

' 'FIG. 7 is a cross-sectional view of the trol valve for controlling the lift.

Referring now to the drawings there is generally pro vided a lift having a super-structure or bolster indicated at A which is supported by a hollow piston B slidably. mounted for vertical reciprocal movement within a cylinder casing or chamber C. I

The upper portion of cylinder C is provided with. a.

pneumatic con-f bearing 17 and a series of glands 18 to provide alignment.

and sealing between the upper portion'of the cylinder. and the outer walls of piston B. Piston B is partially filled with hydraulic liquid in the area as indicated at 2d and the interior of the cylinder is completely filled with hydraulic fluid in the area as indipiston B and depends from the bottom of super-structure A in parallel relation to the piston. The guide cylinder is raised within a sunken well or sleeve E which guides the cylinder for vertical reciprocal movement.

An air control or pilot valve F is connected to two conduits or pipes 26 and 27 which enter the guide sleeve via a longitudinal slot 36 formed therein. Flexible hoses I 31 and 32 are arranged to depend from pipes 26 and 27' respectively and thence extend upwardly to a depending, cut out section 34 on the undersurface of bolster A where the hoses connect to two rigid pipes 35 and 36. A pair of sheaves 33 weighted by a weight 33 are arranged to maintain hoses 31 and 32 in a moderately taut depending loop.

Pipe 35 is fed directly into an air chamber 38 in piston B above fluid area 20 through an air deflecting nozzle 39. Pipe 36 is connected to hydraulic and pneumatic actuating valves G.

Valves G are arranged in a first phase of operation to.

function as a check valve arrangement for allowing the relative to the hydraulic liquid to pass from the inside of piston B into area 21 and in the second phase of operation to allow the free flow of fluid in either direction and to simultaneously bleed air within air chamber 38 of piston B to atmosphere.

In operation control valve G is arranged to move to a first position of operation wherein air is forced through pipe 26, flexible hose 31 and rigid pipe 35 into air chamber 38 so as to force the hydraulic liquid within area 20 of piston B into area 21 of cylinder C thus causing the piston and the entire super-structure to raise.

To lower the device pilot or control valve F is moved to the second position of operation which causes actuating valve (3 to move to its second position of operation wherein the air within chamber 38 is released to atmosphere and the hydraulic fluid within the cylinder is allowed to pass back into the piston thus eifectuating a lowering of the lift.

Control valve F comprises a main body housing 40 having a pneumatic input port 41 opening into an interior manifold or valve chamber 42. To the right side of the manifold, as viewed in FIG. 7, there is provided a check valve 44 which functions to prevent fluid communication from manifold 42. to fitting 45 which is connected to pipe 27 and a check valve 46 which functions to prevent fiuid communication from manifold 42 to fitting 48 connected to pipe 26. The check valves are urged into the closed positions by springs 49 and 50.

' Check valves 44 and 46 are operated by a rocker arm 52 pivoted at 53 to engage alternatively either valv stem or plunger 55 before actuation of valve 4-4 or stem or plunger 56 for actuation of valve 46.

Plunger 55 has on its lower portion a valve head or disk 58 which functions to nest in a seat 59 to close fluid communication between the air chamber 6t? between fit ting 45 and manifold 42. There is sufficient space between plunger 55 and its connected sleeve 63 in which the plunger is reciprocally mounted so that there is fluid communication from chamber 6t) to atmosphere until disk 53 is in sealing contact with seat 59, or alternatively a hole can be provided within the housing forming a fluid vent from chamber 60 to atmosphere.

An actuating projection 68 depends from disk 58 which engages a similar upward projection 69 on valve 44. The two projections 68 and 69 will engage to cause valve 44 to open when slight pressure is applied to plunger 55. However, there is an air escape path to atmosphere so that very little air pressure is generated through pipe 27 until disk 58 makes sealing contact with valve seat 59. This valve therefore functions to provide an air escape from pipe 27 to atmosphere when rocker handle 52 is in its normal position and which further continues the air escape after valve 44 is open and until positive full down ward pressure is applied on the actuating handle. Thus this provides a safety feature which will prevent accidental lowering of the lift when only slight pressure is applied to rocker handle 52. and furthermore provides an escape port by which the actuating valve control mechanism can return to its normal position with control valve F in its normal position.

Valve 46 is operated by moving rocker handle 52 in the opposite direction. Plunger 56 is spring urged upwardly by a spring 70 and is provided with an internal bore 71 into which an upstanding stem 72 projects. When plunger 56 is forced down the end wall of bore 71 makes contact with stem 72 to cause valve 46 to open to cause pneumatic pressure to be applied to pipe 26. This causes valve G to move to its second phase of operation.

. Valve G is connected to two pipes 80 and 61. Pipe 80 depends from the valve down through the bottom of piston B. Pipe 81 depends from the valve to the bottom of piston B and to another pipe 82 which is in fluid com-' munication with area 29 within piston B.

A safety stop mechanism 85 is arranged over the aperture 86 opening into pipe 32. The safety stop mechanism merely comprises a float 88 carried within a perforate tube 89 in such an arrangement that the float will seat over aperture 86 should the liquid level within area 20 drop below the safe limit. This will prevent air from flowing into pipes 80, til and 82.

Valve G comprises a hydraulic liquid check valve 90 which is normally arranged to allow hydraulic fluid to pass from pipe 81 to pipe 86* but not in the reverse direction and which may be actuated to allow free transfer of fluid between pipes 81 and 8h. The valve generally comprises a valve head or disk 91 which is arranged to urge against a valve seat 92 by a spring 87. The disk is unseated from seat 9?. by moving a plunger 93 against the outward projecting stem 94 of the valve. Valve G also comprises an air release valve 95 having a valve disk 96, which mates with the valve seat 97. A spring 98 normally holds the disk against the seat. The valve is in direct liquid communication with air chamber 38 at 99 and will vent air within chamber 38 to atmosphere through vent 100 when disk 96 is unseated from seat 97. A valve actuating stem lttl is connected to disk 96 to allow the disk to be unseated from seat 97.

Actuating valve G also comprises a pneumatic control motor comprising a piston 106 mounted within a cylinder 107. Rigid pipe 36 is connected to one side of the piston so that when air pressure is applied through pipe 27 air will flow through pipe 36 and force piston 106 to move outwardly. The piston is connected by a shaft 109 to a plunger actuating plate 110. The plate is mated to contact valve actuating stem 101 and plunger 93 whenpiston 106 is moved forward. Thus applying air in pipe 26 will cause the motor to disengage disks 96 and 91 from their seating engagement thus allowing free transference of oil between pipes 80 and 81 and venting air to atmosphere.

Plunger 93 is provided with a bore 108 into which stem 94 is reciprocally mounted to provide some loss motion from plunger 93 when actuated prior to the time that disk 91 will be disengaged from seating engagement.

' An actuating handle 115 is mounted on plated 110 50 that the valve'may be manually actuated in the event it should be desired or become necessary.

In overall operation of the device when rocker handle 52 is moved to the left air manifold 42 is communicated into pipe 26 and flows into chamber 38 wherein the air pressure forces the fluid within area 20 to pass through pipe 82, pipe 20, check valve 90 and through pipe 80 toward chamber C. This causes the entire lift to raise.

When handle 52 is released the airwithin chamber 38 is held captive because the air pressure within manifold 42 is of greater intensity than the air within pipe 26. Should the air accidentally escape from chamber 38 it is apparent that check valve 90 functions to prevent fluid transfer from pipe 80 to pipe 81 and thus it would be impossible for the device to be lowered. Should check valve 90 he accidentally released while the air pressure is maintained within chamber 38 the lift would also: stay in the raised position because the air pressure alone would maintain sufficient pressure to prevent fluid transfer from the cylinder back into the piston. This provides a unique double safety feature for the device.

it can be seen that piston 106 is normally in the rearward position because air pressure within pipes 36- -27 is allowed to escape through pipe 36 of control valve F. When handle 52 is moved to the right sufiiciently to cause disk 58 to mate with seat 59 air pressure within manifold 42 is transferred into pipes 27 and 36 thus forcing piston 106 in the forward direction. This causes plate 110 to" As heretoforenoted, a particular object and advantage;

of the preseflt'invention is to'pi'ovide a packaged vehicle lift with substantially all of the component parts, including the pneumatic and hydraulic system, are either pro-assembled at the factory or require no more than ordinary skill and minimum time to assemble and install at the job situs. More specifically, it is observed that the only plumbing in the conventional sense of the word that is required to be done is to run standard size pipes (such as 26 and 27) from the control valve F located to the approximate point where the well or casing E carrying the tubular guide D is to be sunk. With this relatively easy and conventional type of air conduit system installed, it is only necessary for the workmen on the job site to couple by conventional fittings the flexible hose lines 31 and 32 to the pipes 26 and 27. The weight 33 carrying the double sheave 33 functions as a slack takeup mechanism for the flexible hoses and permits the looped hoses to elongate and shorten according to the raising and lowering of the piston and lift super-structure carried thereby. Further, it is seen that the flexible hoses 31 and 32 are completely housed and protected within the confines of the tubular guide D and it is also apparent that the related other portions of the pneumatic and hydraulic system are all contained within the protective confines of the super-structure A orpiston assembly B. Although the present invention has been described in specific reference to a single piston-cylinder ram type vehicle lift in whichthe piston carries a super-structure of desired typefor directly mounting and supporting a vehicle to be repaired; orlubricated, it is appreciated that the scope of the present invention is not limited to single" ram hoists, nor to hoists having any particular type or types of super-structures mounted thereon. In this connection it is contemplated'that the principles of the presour invention are applicable to so-called two-post type lifts in which a first hydraulic ram 'is designed to support and elevate the front end of a vehicle and a second hydraulic ram, usually independently operable from the first ram and mounted in spaced relation therefrom to raise and lower the rear endof the vehicle. Further, it is contemplated that the present invention may be utilized in other types of hoist installations where it is desired to provide a hydraulic-pneumatic drive motor as a power source for lifting hoists by cables or pulleys run from the driving piston of the motor to the vehicle support rails of the hoist itself. The term super-structure therefore is meant to include vehicle supporting rails or bolsters of any suitable or conventional type as well as cable sheaves, pulleys, or other drive mechanisms that constitute a part of a vehicle hoist installation.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirt of the invention as limited only by the scope of the appended claims.

What is claimed:

1. In a piston cylinder type vehicle lift structure of the class in which liquid carried in a hollow lift piston is forced under pressure of air supplied to said piston into a cylinder to cause said piston to elevate, and Wherein the upper end of said piston carries an elevatable super-structure the improvement which relates to a means for supplying air from a compressor source located remote from said lift structure to the top interior of said piston, comprising: a guide tube carried by said superstructure and depending therefrom in parallel spaced re lation to said piston; a guide well below and vertically aligned with and proportioned to slidably receive and guide said depending guide tube; and air conduit means connecting the top interior of said piston to a source of air pressure remote from said vehicle lift; said air conduit means including a conduit section disposed wholly within said tubular housing.

2. in a piston cylinder type vehicle lift structure of a cylinder to cause said piston to elevate, and wherein the 'upper end of said piston carries a super-structure on a which vehicles may be supported and elevated above floor level, the improvement which relates to a means for supplying air from a compressor source located remote from said lift structure to the top interior of said piston, comprising: a guide tube carried by said superstructure and depending therefrom in parallel spaced relation to said piston; a guide well sunk below floor level vertical y aligned with and proportioned to slidably receive and guide said depending guide tube; and air conduit means connecting the top interior of said piston to a source of air pressure remote from said vehicle lift; said air conduit means including at least one flexible hose defining at least one depending loop within said tube; the first end of said hose loop connectedto a conduit leading to the upperinterior end of said piston and the second end of said' hose loop connected to a conduit leading to said source of'air pressure located exteriorly of said tube; said loop.

end 'of said hose loop is connected to the conduit leadingto said source of air under pressure at a point proximate flo'or level.

4. The combination of claim 2 and wherein said loop is provided with slack take-up means to maintain said hose'moderately taut at all times.

carried by the lower extremities of said loop and freely movable up and tube.

6. The combination of claim 2 and wherein the second end of said hose loop is connected to a conduit leading to said source of air pressure at a point of connection located proximate floor level; said guide tube being longi tudinally slotted to permit extension into said tubular housing for coupling with said flexible hose, the said last named conduit leading to said source of air pressure.

7. In a lift the combination of: a cylinder; a hollow piston slidably mounted within said cylinder; hydraulic fluid within said cylinder and partially filling said piston; pipe means establishing fluid communication between the interior of said piston and said cylinder; means to force air into the top portion of said piston to build up pressure to cause a transference of fluid within said piston through said pipe means to said cylinder; check valve means within said pipe means to allow fluid to pass from said piston to said cylinder and not in the reverse direction; air escape valve means for said piston; release means to release said air escape valve means and said check valve means; and means operable to actuate said release means.

8. In a lift the combination of: a cylinder; a piston slidably mounted within said cylinder; said piston having an enclosed chamber; hydraulic fluid within said cylinder and partially filling said chamber; first pip-e means opening to the bottom of said chamber and extending upwardly to a position above said chamber; second pipe means depending to the bottom of said cylinder and opening into said cylinder; check valve means mounted on the top of said cylinder and connected to said first and second pipe means; said check valve means operable in a first position of operation to allow fluid communication only from said first pipe means to said second pipe means and in the second position of operation to allow free fluid communication between said first and second pipe means; air input means opening to the top of said chamber to force air into said chamber; air valve means opening to the top of said chamber and operable to release air pressure in said chamber to atmosphere; and valve con- '5.-' The combination of claim 4 and wherein said last named slack take-up means comprises a weighted sheave;

down within the confines of said guidesoon-eta not means mounted on the top of said cylinder operable to open said air valve means and move said check valve means to the second condition of operation. v 9. In a piston cylinder lift mechanism of the class in which; liquid carried in a hollow lift piston is forced undcr pressure of air supplied to said piston into a cylinder to-cause said piston to elevate, and wherein the upper end of said piston carries an elevatable superstructure, theimprovement which relates to a means for supplying air from a compressor source located remote from said lift structure to the top interior of said piston comprising: air conduit means including at least one flexible air hose. located exteriorly of, adjacent and vertically parallel to said cylinder and communicating between the upper end of said piston and a source of air under pressure-located extcriorly of said cylinder and below said super-struts; ture; the length of said hose being sufficient to raise and lower with said piston; and slack take-upmeans to maim this; said hose relatively taut at all times.

, All. {The combination of claim 9 and wherein there is provided a protective housing encasing said hose and'cartied by and elevatable with said piston and super-structure.-

11. In a lift of, the type having a cylinder, a hollow pis pass only from the interior of said piston into said cylinder, air release means mounted on said cylinder to allow air to escapefrom said piston, a pnuematic motor operable when actuated by pneumatic pressure to release said air release valve means and to open said check valve means, control valve means located at a position remote.

from said lift, means to supply :air pressure to said con trol valve means, said control valve means having a first check valve section connected in- 'fluidcommunication with to interior of said piston and operable to normally prevent the air under pressure within said control valve from passing through said check valve section, a second check valve section in fluid communication with said pneumatic motor, said second check valve section operable in closed position to block fluid communication from the air pressure within said control valve to said pneumatic motor and to open the fluid communication from said pneumatic motor to atmosphere, and operating means on said control valve means movable to a-first position of operation to open said first valve section, said operating means also movable to a second position of operation to open said second valve section to establish fluid communication between the air pressure within said con trol valve to said pneumatic motor and to also close fluid communication between said pneumatic motor to atmosphere. Y

12. in a lift of the type having a cylinder, a hollow piston slidably mounted for vertical reciprocal movement within said cylinder, hydraulic fluid within said cylinder and partially filling said piston, means to establish fluid communication between the interior of said piston and said cylinder, and a bolster mounted onthe top of said piston the improvement comprising: a guide cylinder References Cited in the file of this patent UNITED STATES PATENTS 1,958,960 Warner u--. we Mar. 15, 1934 1,987,083 Smith e.t .t Ian. 8, 1935 1,060,753 Cochin -e NOV. 10, 1935 2,080,114 Cochin May 11, 1937 Grebe Nov. 30, 1954 

